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Tuesday, December 19, 2017

Researchers Discover Shark That May Be 500 Years Old

Researchers studying Greenland sharks in the Arctic have found one that just might be the oldest living vertebrae on the planet. Based on its size, and using radiocarbon dating on tissue from its eye, this particular shark is estimated to be somewhere between 272 and 512 years old, which means it could have been born as far back as 1505 AD.

This particular individual was first spotted by scientists who were conducting a catch and release program during which 28 Greenland sharks were examined. It was notable for its size, stretching 18 feet (5.4 meters) in length, which was an indication of its longevity for sure. Do to its slow metabolism and life in icy waters, the species only grows at a rate of about 1 cm per year.

Unlike other sharks, which have hard, calcified tissue that can be used to detmeurine their age, a Geenland shark has mostly soft tissue instead. In order to determine the age of individuals scientists have begun using radio carbon dating, which examines cells that are taken from the eye. In this case, the dating process gave them the estimated age-range for this particular shark.

To be certain, the 272 to 512 year range is a wide one. The researchers say it is unlikely that this particular shark is actually 500+ years old, but it is quite possible. Their research indicates that it is most likely around 390 years old, which is still pretty mind blowing. Even if it is relatively young at 272 years of age, it is still quite impressive.

Greenland sharks are particularly difficult to observe in the wild since they live in remote places, swim through extremely cold waters, and can dive as deep as 9100 feet (2774 meters). But, researchers are doing their best to learn more about these creatures, and determining their lifespan is part of that process. Just how long they can live is a mystery, but it seems likely that there might be some hardy individual members of the species that are indeed more than a half-century old.